Offset printing



March 29, 1966 w. J. HASELOW ETAL 3,243,337

OFFSET PRINTING Filed Jan. 16, 1965 l9 INVE T0123 20 WILLIAM J: ASELOW BY WILLIAM H. kocH A'r'rvs.

United States Patent 3,243,337 OFFSET PRINTING William J. Haselow and William H. Koch, Wisconsin Rapids, Wis., assignors to Consolidated Papers, Inc., Wisconsin Rapids, Wis., a corporation of Wisconsin Filed Jan. 16, 1963, Ser. No. 251,903 7 Claims. (Cl. 161-36) This invention relates to improvements in offset printing and more particularly to improvements in the use therein of a continuous web of paper in roll form.

As is well known, offset printing comprises the transfer of an ink impression from a lithographic, letterpress, rotogravure, etc., plate which suitably may be carried on a cylinder to a rubber blanket which likewise can be in the form of a cylinder, and then to the paper being printed. This offset printing can be conducted so that both sides of a paper Web may be printed in one pass through the press at the same time in a blanket-to-blanket perfecting web offset press, and in one or more colors, the completed work being either rewound onto another roll, sheeted and piled, or folded in multiple-page signa tures ready for final bindery operations. For such web offset printing the paper may be employed in for example 35 diameter rolls. Conventionally such roll contains from 0 to 3 or more splices.

Since the advent of high-speed Web offset printing the paper roll splice has ben a source of difficulty for press men. Due to the heretofore conventional method of splice construction the splices would often break by delamination, in part due to the great ink tack forces of the press, unless special caution was taken to prevent this such as releasing the press cylinder pressures or slowing the press speed.

Web offset presses run at average speeds of 16,000 to 20,000 signatures per hour which means about 600 feet of paper per minute flows through such a press and an individual particle of paper goes through the press in less than five seconds. In this five seconds the particle receives up to four impressions of different colored inks, is dried by direct-flame contact where it is raised from room temperature to about 280 F., and then cooled again to near room temperature, following which it is generally cut to the proper length and/or folded into booklets or signatures.

Heretofore, reduction or releasing of the cylinder pressures or slowing of the press speed was necessary whenever a standard mill splice went through the press to eliminate the possibility of the splice delaminating or breaking which would cause the press to be shut down from 30 to 45 minutes. Such action would cause the waste of 200 or more signatures and/or cause a delay in the printing process as indicated. The pressman thus had the option of gambling on a splice break or releasing the press cylinder and losing several hundred signatures. Either option caused waste of time and material and unnecessary expense.

An ideal paper roll splice should go through a web offset press at high speeds without having to lift cylinder pressure or without having to reduce press speed and with loss only of the signature in which the splice occurs, and it is an object of the present invention to make such ideal situation possible.

It has been found that heretofore the majority of the splice failures in web offset paper was primarily caused by the delamination of the leading edge of the standard mill splice which comprised overlapping one end portion of the torn and resulting serrated edge over the adjacent torn edge with adhesive material disposed in between. Furthermore, the exposed leading edge of the splice, resulting from the tearing off of the overlap tabs after making the heretofore standard mill splice, has a serrated edge which is quite susceptible to damage when the splice is subjected to high ink tack forces as it leaves a cylinder after impression contact.

The present invention makes it possible for a pressman to completely ignore a paper roll with splices therein and to treat it as if it were a continuous web, other than the necessity to remove the signature or impression containing the splice at the output end of the press.

The splice of the present invention can even be considered to be stronger than the paper itself and will not delaminate even under severe conditions where web offset paper naturally delaminate. Moreover, the spliced paper of the present invention establishes the endurance limit of the roll and not the splice and because of its superior physical characteristics the spliced paper of the present invention cuts loss of impressions and spoilage to a minimum and allows the pressmen to run at a constant speed and pressure appropriate for the grade of paper being used, thereby allowing the printer to obtain more signatures or impressions per hour with attendant economy.

Thus, the overall object of the present invention is to provide a spliced web of offset printing paper in roll form wherein the tendency of the spliced paper to be weaker than a spliceless web, and the tendency of such spliced web to delaminate, are substantially eliminated.

The object of the invention, its details of construction and economies thereof, will be further apparent by reference to the following specification and accompanying drawings wherein:

FIG. 1 diagrammatically illustrates a web offset press of the blanket-to-blanket perfecting type.

FIG. 2 diagrammatically indicates a side edge view of a mill splice of the heretofore conventional type.

FIG. 3 is a side edge view of a splice made in the web of offset printing paper in accordance with the present invention.

FIG. 4 is a view similar to that of FIG. 3 of a modified arrangement.

FIG. 5 is a plan view of the spliced web of FIG. 3 formed in accordance with the present invention.

Referring to the drawings, and particularly to FIG. 1, there is diagrammatically shown a web offset press of the blanket-to-blanket type comprising two units 11, 11 for printing two colors on each side of a single web. It will be understood that one unit 11 may be empoyed and thereby one color printed on each side of the web or a greater number of such units may be employed such as for example four disposed in a series which can thus print four colors on each side of the web 10 which is supplied from the roll 12.

In the offset press arrangement shown in FIG. 1, the web 10 passes between two opposed rubber blanket covered cylinders 13, 13, each acting as the impression cylinder for its mate in the printing unit. It will be understood, although not shown, that web tension in both lateral and running directions is controlled to maintain proper register and means are also provided to retain proper pressure on the blanket cylinders 13, 13 by conventional means not shown. It will also be understood that this means for regulating pressure applies not only to cylinders 13, 13 but to other rolls and components of the units 11 such as on the plate cylinders 14, 14 which act against the blanket cylinders 13, 13. It will of course be understood although not shown that the units 11 comprise suitable inking means conventional to offset printing presses using any type plate.

It will also be understood, although not shown, that the web 10 after passing through the last printing unit 11 is then directed to drying by passing through an oven following which it is cooled by means of cooling rollers,

Patented Mar. 29, 1966 imprinted if desired, and then re-rolled, cut or folded as previously indicated.

The web or offset paper 10 is desirably printed with heat set inks where most of the ink sets on top of the paper where it can be quickly dried with a minimum penetration into the paper and thus achieves greater density of pigment and brighter colors for a given amount of ink. The offset web thus desirably has a degree of water repellency and limited ink absorbent properties although these can be reduced in high-speed web offset printing.

Heretofore in making up a roll of paper one or more breaks often occurred and these were spliced together as for example shown in FIG. 2 wherein two web end portions 15 and 16 were adhered together by disposing between them a strip of splicing tape 17 carrying pressure sensitive adhesive on both of its opposed faces, following which web edge portions 18 and 19 were torn off in as smooth a manner as possible. However, this left the edges 18 and 19 with a typical torn character having a marked tendency to be damaged when subjected to the action of ink tack forces as the splice leaves the blanket cylinders 13 after contact for impression.

In one form of the present invention as shown in FIG. 3 the end portions 15 and 16 of a ruptured web 10 are first joined together in a manner similar to that shown in FIG. 2 by disposing between their overlapped ends a strip of adhesive tape 17 carrying pressure sensitive adhesive on its opposed faces. 20 carrying adhesive on only one face thereof is bridged over the end portions 15 and 16 of the torn web to join them into a continuous web in a manner whereby the tape 20 overlies the torn and serrated edge 18 of the upper web portion 10. It is understood, of course, that the tape 20 is pre-forrned with cut lateral edges 21, 21 so that no problem of free fibers or serrations results.

In accordance with the preferred practice of the present invention, the strip 20 is disposed on a bias after pretearing the web end portions 15 and 16 in a similar manner.

It will also be understood that in accordance with the practice of the invention, the intermediate tape 17 and the overlying tape or tapes 20 are composed of re-pulpable fibrous material and that their pressure sensitive adhesives are soluble or dispersible in water or caustic solutions so that the portions of the web to which they are adhered can be reused.

The tapes 17 and 20 are preferably as thin as possible, and the outer tape 20 is preferably of an absorbent uncoated paper character, although it may comprise a coating. However, the character of the strip 20 should be distinguished from those of non-fibrous or entirely nonporous material such as continuous plastic webs which would cause offsetting. An example of the fibrous web materials 17 and 20 and their component composition is shown for example in United States Patent No. 2,838,421.

Although in the foregoing we have thus far described a single Strip 20 carrying adhesive on one face thereof and which satisfies the problems hereinbefore encountered and described when the splice web is moving in the direction of the arrow and the edge 18 is thus the leading edge, a similar strip 20 is applied over the opposed face of the splice bridging the edge 16 and the opposed web 10, and overlying the torn web end 19. This trailing edge 19 is covered to preclude the possibility thatwhen the web is wound up in the form of the roll 12 it will be rewound by the printer which would cause the leading Web end to become the trailing web end and vice versa.

The modified form of construction shown in FIG. 4 which is used when splice thickness is a factor is substantially the same as that shown in FIG. 3, with the exception that at no point are there more than three superimposed layers as distinguished from the arrangement in FIG. 3 where in the area of the splice there are four superimposed Thereafter, a strip of adhesive tape layers. Thus, in the arrangement of FIG. 4 the end portions 15' and 16' of the component torn web portions 10, 10 can be considered to be relatively longer than the similar web ends 15 and 16 of FIG. 3 so that the intermediate double adhesive coated strip 17 in the arrangement of FIG. 4 is disposed only between the Web end portions 15' and 16, with web end portions 15' and 16' extending beyond the edges of the intermediate adhesive strip 17. Thus, the single adhesive coated outermost adhesive strips 20, 20 when overlying the torn edge portions 18' and 19' do not overlie any portion of the interposed strip 17.

Although we have shown in FIGS. 3 to 5 the preferred embodiments of our invention, it will be understood by those skilled in the art that other arrangements comprehended by the scope of the appended claims may be made without departing from the broader scope of our invention.

In employing the spliced web of the present invention, tests have indicated that our new type splice resisted delamination and was of greater strength than the web per se. For example, two rolls having four splices each were run in a four unit press at a speed of 16,000 signatures per hour, with the web leaving the oven at 280 F., and with the cylinder pressure remaining constant during the entire run. The four splices in each roll went through the press without any hint of difliculty. Each signature following each of the eight splices were satisfactory and usable.

. We claim:

1. A spliced paper web comprising paper strip material carrying pressure sensitive adhesive on the opposed faces thereof and disposed between overlapped substantially transversely extending severed end portions of a paper Web, said strip material securing said end portions together, and added paper strip materials carrying pressure sensitive adhesive on their undersides only and overlying the said severed end portions and the adjacent main web body to join them into a continuous web, the said strips extending completely across the joined web in a substantially transverse direction the entire tape being repulpable and the pressure sensitive :adhesive being soluble or dispersible in water or caustic solution.

2. The spliced web of claim 1 wherein said severed end portions are of torn serrated character.

3. The spliced web of claim 1 wherein said overlying strips have straight cut defining side edges and completely overlie said severed end portions.

4. The spliced web of claim 1 wherein the overlying strips are spaced from the side edges of the interposed strip.

5. The spliced web of claim 1 wherein the overlying strips overlie the side edges of the interposed strip.

6. The spliced paper web of claim 1 wherein said strips extend in a substantially oblique direction across the web.

7. The spliced paper web of claim 1 wherein said strip material is of a fibrous base pulpable character.

References Cited by the Examiner UNITED STATES PATENTS 948,350 2/1910 Skidmore 74-231 2,048,895 7/1936 Rosen -c 931.1 XR 2,060,906 11/1936 Snyder 161145 XR 2,446,576 8/1948 DeVry 156505 2,506,915 5/1950 Bishop 161-36 2,550,520 4/ 1951 Bennett 161-36 XR 2,838,421 6/1958 Sohl 1l7l22 FOREIGN PATENTS 814,538 6/1959 Great Britain.

ALEXANDER WYMAN, Primary Examiner.

DAVID KLEIN, Examiner.

I. H. STRNISHA, R. A. FLORES, Assistant Examiners. 

1. A SPLICED PAPER WEB COMPRISING PAPER STRIP MATERIAL CARRYING PRESSURE SENSITIVE ADHESIVE ON THE OPPOSED FACES THEREOF AND DISPOSED BETWEEN OVERLAPPED SUBSTANTIALLY TRANSVERSELY EXTENDING SEVERED END PORTIONS OF A PAPER WEB, SAID STRIP MATERIAL SECURING SAID END PORTIONS TOGETHER, AND ADDED PAPER STRIP MATERIALS CARRYING PRESSURE SENSITIVE ADHESIVE ONTHEIR UNDERSIDES ONLY AND OVERLYING THE SAID SEVERED END PORTIONS AND THE ADJACENT MAIN WEB BODY TO JOIN THEM INTO A CONTINUOUS WEB, THE SAID STRIPS EXTENDING COMPLETELY ACROSS THE JOINED WEB IN A SUBSTANTIALLY TRANSVERSE DIRECTION THE ENTIRE TAPE BEING REPULPABLE AND THE PRESSURE SENSITIVE ADHESIVE BEING SOLUBLE OR DISPERSIBLE IN WATER OR CAUSTIC SOLUTION. 